JCN tests P365-380

[JCN]

Comes into the LGS today and I think I might have time to do some testing this afternoon.

Planning on LabRadar chrono compared to G42 and Kimber Micro 380.

I’m also planning on seeing what parts fit in the 9mm slide and vice versa.

I would also like to compare it to subminor FMJ 9mm because if people carry ball ammo in 380 it’s probably reasonable to compare it to weak 9mm ball ammo as well.

If there are specific things people would like to see, let me know this morning so I can do it this afternoon.

LGS has a Kahr P380 on consignment that I’m tempted to pick up for comparison sake.

[peterb]

Thanks for doing this! I think comparison with any lower-recoil 9mm would be interesting: Standard 147, factory “gamer” loads like Syntech 150 or Ely Minor, etc.

[Polecat]

Can’t wait, you enabler you!

[Jim Watson]

I would also like to compare it to subminor FMJ 9mm because if people carry ball ammo in 380 it’s probably reasonable to compare it to weak 9mm ball ammo as well.

I load subminor 9mm to shoot my Glock 43 in GSSF Pocket Division.

I can see a case for 9mm Lite in a pocket pistol. But does it need to be ball? Might an ammo company with a R&D shop get out a f 110 bullet with a good compromise between penetration and expansion? There are several .380s that did for Luckygunner.

[octagon]

I'm curious how the slide or other parts compare between 380 and 9mm versions specifically if the 380 slide works on 9mm gun with 9mm mags and if it would/will run. Also interested in the mag spacer or differences. Are all parts interchangeable ?

For shooting comparing light lower velocity 9mm to heavier full power 380 and then normal 9mm in how the differences are in comparison.

Thanks for sharing.

[JCN]

I'm curious how the slide or other parts compare between 380 and 9mm versions specifically if the 380 slide works on 9mm gun with 9mm mags and if it would/will run. Also interested in the mag spacer or differences. Are all parts interchangeable ?

For shooting comparing light lower velocity 9mm to heavier full power 380 and then normal 9mm in how the differences are in comparison.

Thanks for sharing.

I’m also very interested if I can put the 380 barrel in my 9mm SAS slide.

Or put a 9mm barrel into the 380 lighter slide and have a lighter pocket / carry 9mm.

I suspect putting 380 in 9mm mags would work like shooting 40SW out of a Glock 20.

But I’ll test.

[JCN]

85220

It is so light that it feels like their pellet gun.

[1Rangemaster]

JCN-
Sir, you are certainly a better competitive shot than I am. You are also admirably curious and inventive.

BUT, PLEASE EXERCISE CAUTION WHEN SWITCHING PARTS AROUND. The .380 is very different in pressure than a 9x19mm- the 9mm operates at a distinctly higher pressure. That’s why .380s are typically smaller and lighter.

I appreciate your passion for shooting; don’t let that hurt you.

[JCN]

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85223

Lightening cuts on slide.

9mm barrel doesn’t fit because OD and breech face differences probably to prevent inadvertently mixing the two.

YVK the recoil spring does work in the 9mm and would be a good option for compensated 9mm.

[JCN]

85225

Very mild shooting!

380 loads fine using the 9mm mags no spacer (probably was done so people don’t put 9mm in 380 mags by accident).

In comparison same 380 ammo shot through a 9mm SAS:

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[JCN]

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[lwt16]

25 yard group if you are able.

Thanks in advance.

[Mike C]

JCN can we see mag breaker when you have time? I am super curious about these. Also how does it do ejecting a live ball round? I remember the G42 having trouble getting the Geco ball rounds racked out if you needed to unload. Curious if unloading is as easy as loading. Also how hard is the slide to run? Soft like S&W M&P EZ or about the same? I am looking hard at this for my aging mother. Thank you.

[JCN]

25 yard group if you are able.

Thanks in advance.

Hi thanks for all the P365 armorer posts you have shared!

Question, are you looking for the best case mechanical 25 yard accuracy or how shootable it is at 25 yards?

If the former, I’ll put a red dot on it and bring a bench rest to the range to get a group for you.


JCN can we see mag breaker when you have time? I am super curious about these. Also how does it do ejecting a live ball round? I remember the G42 having trouble getting the Geco ball rounds racked out if you needed to unload. Curious if unloading is as easy as loading. Also how hard is the slide to run? Soft like S&W M&P EZ or about the same? I am looking hard at this for my aging mother. Thank you.

Will do. I get the sense that it would be usable for aging / arthritis.

Briefly it seems softer sprung than the G42 but maybe stiffer than an EZ from what I remember. It’s stiffer than the Kimber Micro 380 when the hammer is pre-cocked. That’s the softest you’ll find.

But if she puts a dot on the P365-EZ that also helps with racking.

I’ll try and rig up a pull gauge for the slide.

Will also break down the mags.

[JCN]

Subminor 124gr 9mm

85234


Shooting 99gr Federal HST 380

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The Federal feels milder.

Some weights:

P365-380

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Versus G42 with NINE round extended magazine plus magguts

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Versus P365 SAS

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Some dimensions of the 10 round P365-380 versus 9 round extended G42

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The front sight of the P365-380 is the plain tritium dot, not the green X-ray.

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[JCN]

So it’s interesting that the P365-380 optic cut is shallower than the P365XL cut.

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[JCN]

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Shorter follower and spacer

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Spacer is connected to floor plate

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Different mag spring too.

[JCN]

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The Tactical Development Flush Spacer replaces the pinky extension without changing the floor plate so works without change in function and allows use of the XL grip module if interested.

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[JCN]

Plate cover removed (it’s plastic)

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A lot of Holosun 507k mounts use M4 flat head bolts.

Looks like the plate screws are T9 torx and M3.

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[Mike C]

JCN I could nerd out on the differences all day. Thank you for all the info so far and you nailed what I was looking for in terms of ease of loading. Looks like I'll have to get my mother one and one for me to tinker with. This might be a perfect trainer for my son since he is only 9. I hope we end up with a 22LR version of the 365 but in the mean time this will certainly do. Thanks!

ETA: The plastic cover plate make sense to keep weight down and as a cost cutting method to a degree. I wonder if the shallower cut was to balance slide weight, unlocking, and spring wear but if this is the case I can't help but wonder why they wouldn't just make fewer relief cuts and go to a casted cover plate. But I imagine no one really cares about the cover plate durability but me.

[JCN]

So looks like M3x12 is perfect.

Quite deep engagement.

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[Mike C]

So looks like M3x12 is perfect.

Quite deep engagement.

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I've got to ask, source for screws? That is what looks to be a very well put together assortment.

[lwt16]

Hi thanks for all the P365 armorer posts you have shared!

Question, are you looking for the best case mechanical 25 yard accuracy or how shootable it is at 25 yards?

If the former, I’ll put a red dot on it and bring a bench rest to the range to get a group for you.
.

Yes, the former please.

I’d like to see a nice mid 90s at 25y.

Regards.

[JCN]

I've got to ask, source for screws? That is what looks to be a very well put together assortment.

I have a lot of optics and I move them around from application to application a lot.

So I have piles of screws lying around, as you know body heights are different so sometimes length of screws need trimming with the Dremel.

I got a little tired of it so I also bought a bunch of metric flat head screws for Holosuns.

And cap screws for Trijicon and Shield.

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I use E6000 on the optic to slide interface so it takes a lot of the shear loading off the screws so they don’t have to be crazy strong. On this slide they have retaining posts too.


Yes, the former please.

I’d like to see a nice mid 90s at 25y.

Regards.

Will do. Mounted an optic with a 2 MOA dot that should work. I’ll see what I can do for you.

[JCN]

So I thought I would do a little walk through on my optic mounting process. I move dots around so I don’t want a mounting setup that can’t be undone without stripping heads and I also want something that could last 15k rounds.

I use the same mounting approach in pretty much everything from Carry Optics guns to revolvers.

I have not had any optics loosen, screws fail, etc.

Step 1: check screw engagement depth without optic.

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Step 2: Alcohol clean slide, bottom of optic and screw threads and underneath the cap head.

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Step 3: Small dollop of E6000 on underside of optic. This reduces shock and sliding of the optic and prevents launching it if the screws were to fail. It’s also removable easily anytime.

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Step 4: Press optic onto slide and squish the E6000 to distribute.

Step 5: Very light application of blue loctite at tip of screw and underneath cap head

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Step 6: Install screws and silver sharpie screw head at 6 o’clock position. By using 6 o’clock I don’t have to make the optic itself.

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Step 7: Zero with Wheeler laser.

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Done.

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Should be ready for 25 yard bench rest tomorrow!

Note that the shallow optic cut means that the integrated rear sight is useless.

Which is why I liked the original rear sight delete of the XL.

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[JCN]

Mike C here’s with a Lyman gauge pulling the slide.


https://youtu.be/ZAOJONgP-20

[idahojess]

Thanks for the thread -- everything feed okay so far?

[JCN]

I think this is what Clusterfrack was doing with his P07.

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Because this optic cut is shallower, the ears of the integrated optic sit above the factory rears.

So if you use the integrated optic rear with the factory front you get dot in the middle of the window.

So if the dot didn’t work, if you lined up the integrated rear and the factory front you would hit whatever is framed by the window…

[Chuck Whitlock]

I load subminor 9mm to shoot my Glock 43 in GSSF Pocket Division.

I can see a case for 9mm Lite in a pocket pistol. But does it need to be ball? Might an ammo company with a R&D shop get out a f 110 bullet with a good compromise between penetration and expansion? There are several .380s that did for Luckygunner.

A little late to the party, but in reference to the above question:

https://www.hornady.com/ammunition/handgun/9mm-luger-100-gr-ftx-critical-defense-lite#!/

No clue how it shakes out in gel testing.

[JCN]

But JCN… how does it shoot?!!

Soooo pleasant and easy.

I think softer than the G42.

No sharpness or snappiness.

I used 9mm magazines for all these shooting tests to support a hypothesis.

I used Federal HST 380 and Geco target ammo.

No issues.

Big thanks to JCS who linked me the Primary Arms sale that allowed me to buy this.

I appreciate my friends who look out for me!


https://youtu.be/KljeXFXl-N0

[Clusterfrack]

I think this is what Clusterfrack was doing with his P07.
So if you use the integrated optic rear with the factory front you get dot in the middle of the window.
... if the dot didn’t work, if you lined up the integrated rear and the factory front you would hit whatever is framed by the window…

Exactly. I strongly prefer this setup to irons aligned POA/POI because that requires either full co-witness obscuring the optic or a different index.

[tlong17]

GLOCK 42 KILLER

I wonder if there is any substantial long term performance difference when using the heavier aluminum optics compared to the polymer Romeo Zero. They're only a half ounce difference but maybe that's enough. I know the Zero isn't great but on a .380 it might be fine?

[JCN]

GLOCK 42 KILLER

I wonder if there is any substantial long term performance difference when using the heavier aluminum optics compared to the polymer Romeo Zero. They're only a half ounce difference but maybe that's enough. I know the Zero isn't great but on a .380 it might be fine?

I’m not sure what you’re getting at?

Personally for me, the shortcomings of the Romeo Zero are inherent to the optic itself and not the caliber.

I have a few Romeo Zero.

For that window size, I prefer the 507k because:

Romeo Zero:
1. Battery life is shorter
2. Batteries are more PITA to change. Over the life of the optic you’ll spend the $$ difference between that and a Holosun re-zeroing if you keep it long enough.
3. Off-on-intensity is a PITA to change.
4. Windage and elevation adjustment isn’t tactile and requires a small Allen key.
5. Polymer body with open underside exposes battery and electronics to elements.
6. Circle dot reticle of the Holosun gives a larger virtual window for dot tracking.

I think the Romeo Zero works fine as a budget optic. There are just better options for not a lot more $$.

The only upside to the Zero is cost, IMO.

[tlong17]

I’m not sure what you’re getting at?

Personally for me, the shortcomings of the Romeo Zero are inherent to the optic itself and not the caliber.

I have a few Romeo Zero.

For that window size, I prefer the 507k because:

Romeo Zero:
1. Battery life is shorter
2. Batteries are more PITA to change. Over the life of the optic you’ll spend the $$ difference between that and a Holosun re-zeroing if you keep it long enough.
3. Off-on-intensity is a PITA to change.
4. Polymer body with open underside exposes battery and electronics to elements.
5. Circle dot reticle of the Holosun gives a larger virtual window for dot tracking.

I think the Romeo Zero works fine as a budget optic. There are just better options for not a lot more $$.

The only upside to the Zero is cost, IMO.

I'm more wondering about whether a half an ounce in weight makes a difference when comparing a 507k to a Zero. There is no doubt the 507k is the better stand alone optic.

This is mere pondering about whether weight of the optic really matters, in particular on a .380.


Wanted to come back and update. I now have had a 507k in use for as many rounds and the R0. The R0 is a joke. You can get a 407k for the same price and FAR better ability to

1. Adjust zero
2. Adjust brightness
3. Use built in rear sight for cowitness
4. Have a dot that doesn’t look like shit
5. Actually mounts flush to the slide without sticking up at the point nearest the ejection port.
6. Holds a zero
7. Replace the battery without removing optic and rezeroing
8. Have a battery last longer than a month on average

$50 bucks more and you can get some reticle options in a 507k. All that in a fairly sturdy aluminum housing that performed well in Aaron Cowan’s tests. Why the hell would anyone buy the Romeo Zero? I don’t even know what to do with mine. Throw it in the trash?

[JCN]

I'm more wondering about whether a half an ounce in weight makes a difference when comparing a 507k to a Zero. There is no doubt the 507k is the better stand alone optic.

This is mere pondering about whether weight of the optic really matters, in particular on a .380.

Ha! Gotcha. My personal view is that the weight of the optic does not matter unless the system doesn’t have enough margin engineered into it.

Since Sig is now marketing the Romeo Zero Elite with a shroud, I’m guessing that they have enough margin that the 1/2 ounce doesn’t get near the end of their functional engineering.

The slide is light and the RSA light. Should be good with many different optics. There probably is a weight limit so if someone tried to use an adapter and put a 509t on it, probably could induce some failures.

[JCN]

I plan on trying to shoot a 25 yard bench group today.

Any other requests before I put it away?

[D-der]

Just out of curiosity, is it noticeably anymore pocket-able than a 42 or 365 9mm?

[octagon]

Any chance you could get the weights of the slide, complete upper(slide RSA and barrel) and lower assembly between 9 and 380 versions. I'm curious if the lowers are identical and the changes are all in the upper or slide. Also is there any difference in the barrel locking lug shape or angles between 9 and 380? My curiosity is whether Sig just reduced weight and changed springs or reduced the locked up timing or speed of locking and unlocking between calibers.

[JCN]

Just out of curiosity, is it noticeably anymore pocket-able than a 42 or 365 9mm?

Definitely more pocketable than the 9mm due to the weight difference.

Probably similar to a G42 except G42 is slimmer (but much reduced capacity).


Any chance you could get the weights of the slide, complete upper(slide RSA and barrel) and lower assembly between 9 and 380 versions. I'm curious if the lowers are identical and the changes are all in the upper or slide. Also is there any difference in the barrel locking lug shape or angles between 9 and 380? My curiosity is whether Sig just reduced weight and changed springs or reduced the locked up timing or speed of locking and unlocking between calibers.

From earlier in the thread:

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Barrel locking looks the same but I can take a picture from the side later. Probably doesn’t matter as the barrels don’t fit in the cross caliber slides anyway.

As per the press releases, same lowers just spacer in the 380 mag (that is more administrative than functional).

I think just reduced weight of slide and spring as the functional differences.

Any advertised weight differences in the gun are due to the upper.

About 2.5 oz.

[JCS]

I plan on trying to shoot a 25 yard bench group today.

Any other requests before I put it away?

Maybe I missed it but is it compatible with a manual safety?

[JCN]

Maybe I missed it but is it compatible with a manual safety?

Yes, the lower is functionally identical.

I plan on shooting it today from a rest using the WC module and manual safety.

[JCN]

Yes, the former please.

I’d like to see a nice mid 90s at 25y.

Regards.

85320

From a bench rest at 25 yards.

10 shots in about a minute total because I don’t have that much patience.

97-5x

I think mechanically the gun can probably do 100. I called the three shots in the 9 ring left with too much trigger sideways pull.

[lwt16]

85320

From a bench rest at 25 yards.

10 shots in about a minute total because I don’t have that much patience.

97-5x

I think mechanically the gun can probably do 100. I called the three shots in the 9 ring left with too much trigger sideways pull.

97-5X

Dangit! Sure can’t justify another one this quick!

Thanks for spending the ammo.

Regards.

[RancidSumo]

Very interested in this. When it was first announced I posted in some early thread that it sounded stupid/useless and had a few people point out that the reduced recoil could be a significant benefit for some. Since then, I've watched my mom struggle to handle SD loads out of a 9mm 365. May need to grab one of these and ship it up to her.

Thanks for putting it to the test.

[willie]

Weight of slide is a factor in reducing slide velocity. Wouldn't the 9mm slide be heavier than the 380's slide? If I missed weight comparison, then I apologize for the post. My .45 ACP Shield's side had serrations on the underside to retard velocity.

A most infesting thread, Mr. OP.

[JCN]

Weight of slide is a factor in reducing slide velocity. Wouldn't the 9mm slide be heavier than the 380's slide? If I missed weight comparison, then I apologize for the post. My .45 ACP Shield's side had serrations on the underside to retard velocity.

A most infesting thread, Mr. OP.

Hello, the 9mm slide is ~2.5 oz heavier than the 380.

Slide velocity between the two is difficult to meaningfully compare because the power of the caliber is different.

So even if the velocity of the slides are the same, the power of the cartridge that the spring and slide (and shooter) have to buffer is very different. That’s what drives the difference in felt recoil.

Basically if you get hit by a bicycle rather than a motorcycle, even if they’re both going the same speed….

[alohadoug]

JCN - thanks for doing all of this...and I hate you for doing all this. I'd just about decided I didn't need to pay attention to these and now it might be the answer to my issues (hand issues - nerve/ligaments).

Are there any differences to the slides between the .380 and 9mm? I know SIG's site says they're suppoed to be the same but...I'm curious if the .380 will fit in the Aholster pocket holster for the 9mm. :confused:

[JCN]

alohadoug

External slide dimensions are the same.

Optic cut is forward compared to an X/XL so holster interference there can be an issue, but heat gun +/- Dremel solves a lot of holster issues….

[crosseyedshooter]

alohadoug

External slide dimensions are the same.

Optic cut is forward compared to an X/XL so holster interference there can be an issue, but heat gun +/- Dremel solves a lot of holster issues….

Pardon me for bumping this thread. I’m late to the .380 club; having just recently assembled a P365-380 to help my wife ease into the P365 game. I’ve already spent more money on ammo than the gun!

I guess it’s common knowledge by now; the top of the .380 slide is ever-slightly lower than the 9mm P365 by about 2mm. So, the .380 may rattle around in hard P365 holsters. You can see the gap between the top of the slide and the holster in the pic below:

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This also means the optic cut is shallower than the regular P365 so red dots are unlikely to co-witness with the factory-height sights.

The regular P365-380 comes with older-style Siglite three-dot nightsights. Mine had #8 front with #6 rear. I replaced them with Xray3 SOX10007. For me, the .380 POI is higher than the 9mm using same sight picture. Where the 9mm impacts at the dot (combat sight picture?), the .380 impacts at the too of front sight (center hold?). Some of the newer special edition P365-380 (Rainbow (https://www.sigsauer.com/p365-380-rainbow.html), Rose (https://www.sigsauer.com/p365-380-rose.html), etc.) now come with Xray3 sights.

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Finally, I’ve had great luck shooting PMC 90gr FMJ and 1776 75gr Lead-free ammo but Hornady Critical Defense 90gr simply won’t feed in this gun. I’m kind of peeved since I bought a case of the stuff.

Hornady Critical Defense 90gr .380 failure to feed every two to three rounds with Sig factory .380 magazines.

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